Module 4Physics Paper 2 Section B

1. Many uses of radioactivity involve the decay of radioisotopes.

Table 1 shows an equation of a reaction before and after an alpha decay.

Alpha decay

Before reaction After reaction

Equation 214Po 84

210Pb + 4He 82 2

Table 1

Table 2 shows an equation of a reaction before and after a beta decay.

Beta decay

Before reaction After reaction

Equation 14C 6

14N + 0e 7 -1

Table 2

a) i) What is meant by radioisotopes?[1 mark]

ii) Using the information given in Table 1 and 2 and your knowledge on radioactivity, compare and contrast alpha decay and beta decay.

[5 marks]

b) In the explosion of an atomic bomb, only 500 g of uranium of its initial mass is converted to energy in 1 m s-1

Calculate the power of the bomb.(Speed of light, c = 3 x 108 m s-1)

[4 marks]

Module 4Physics Paper 2 Section B

c) The Malaysian Institute for Nuclear Technology Research (MINT) proposed to develop nuclear energy in Malaysia because the current fossil fuels reserves are estimated to be depleted soon.

Diagram 1 shows a nuclear energy power station.

Diagram 1

Using your knowledge on radioactivity, suggest and explain the safety precautions required to operate the nuclear power station.

[10 marks]

Module 4Physics Paper 2 Section B

2. Often, like following natural disasters like tsunami ,World Food Programme of

United Nation will supply vitamin – fortified high energy biscuits to the affected area.

These biscuits are essential to give people energy and strength while they wait for

help.

If the biscuits cannot be brought in by road, they are dropped by plane or helicopter.

Using appropriate physics concepts, suggest and explain suitable designs or ways so

that these biscuits can be dropped by a plane or helicopter and reach the ground

suffering as little damage as possible.

[10 marks]

Module 4Physics Paper 2 Section B

3. Diagram 2.1 and 2.2 below show the two generators and their respective output wave forms.

Diagram 2.1 Diagram 2.2

(a) What is mean by electromagnetic induction? [1 mark]

(b) i. Using diagram 2.1 and 2.2, compare the connection at the ends of the coil, the contact between the rings and the carbon brushes and the output wave forms.

[3 marks]

ii. State the type of generators in diagram 2.1 and 2.2 respectively. [2 marks]

(c) Diagram 2.3 shows an electromagnetic relay in the starter system of a car.

Diagram 2.3

A current of up to 200 A is required to start up the car engine. Explain how the small current from the low voltage supply can start the car engine.

[4 marks]

Module 4Physics Paper 2 Section B

(d) Diagram 2.4 shows a generator. Suggest ways of increasing the efficiency of the generator. Give your reasons.

[10 marks]

Diagram 2.4

output

Module 4Physics Paper 2 Section B

4. A researcher is to investigate the various properties of different materials to measure temperature. The formula to calculate temperature is

o C

where xθ is the value of property of the material at θ temperature.x0 is the value of property of the material at ice point.x100 is the value of property of the material at steam point.The following table shows three types of thermometer and their properties

Value of propertyTypes of

thermometerProperty Ice point Steam point Room

temperature

Mercury in- glass

thermometer

Length of mercury (cm)

3.50 15.50 l

Resistance thermometer

Resistance (Ω) 75.00 63.00 64.99

Gas thermometer

Pressure (kPa) 110 80 85.1

a) (i) What is meant by steam point of a material ? [1 mark]

(ii) There are two fixed points in the calibration of a temperature scale. Name the two fixed points.

[2 marks]

(iii) Find the room temperature in oC recorded by the resistance thermometer. [3 marks]

Module 4Physics Paper 2 Section B

(iv) Find the room temperature in oC recorded by the gas thermometer. [2 marks]

(v) If the value of room temperature recorded by using gas thermometer is more reliable, what is the value of property l , at room temperature for mercury- in-glass thermometer?

[3 marks]

(b)

The figure above shows a kind of thermometer using two metals that are riveted together.

(i) Describe the principle of this thermometer briefly. [4 marks]

(ii) Discuss the advantages of the use of this kind of thermometer over the liquid- in- glass thermometer in some electrical appliances.

[5 marks]